1. Field of the Invention
The present invention relates to a cassette for insertion in a wedge-shaped ink well of a printing machine.
2. Description of the Related Art
A cassette for a wedge-shaped ink well is known from prior art reference DE 43 15 595 C2. The cassette in this prior art reference has two side walls connected by a bottom and a back wall. Attached to the bottom of the cassette are elastically deformable sealing elements. These elastically deformable sealing elements extend parallel to a duct roller and act against an elastically flexible ink blade in the wedge-shaped ink well. The cassette includes handle elements permitting the cassette to be handled outside of the wedge-shaped ink well. To prevent ink from flowing out of the cassette during its insertion into or removal from the wedge-shaped ink well (the position of which, including the duct roller, cannot be changed), the cassette includes a blocking gate which slides into blocking position along lateral guides in the open longitudinal side of the cassette. The blocking gate prevents ink from flowing out of the open longitudinal side.
The prior art reference includes a seal for the cassette on its front relative to the duct roller. However, the seal is complicated and prevents the duct roller from being inked in unlimited fashion over the full width of the ink well. An addition problem with this prior art device is that the three-point support for the cassette in the wedge-shaped ink well poses the risk of unstable positioning due to the hydrodynamic forces acting in the run-in space of the duct roller.
Another prior art reference, EP 0 508 031 A1, describes a cassette that can be suspended on the external gear of the ink duct by an angular piece and closed by a gate. To suspend the cassette, vertical clearance is needed relative to the duct roller. The elastically deformable ink blade in this reference disadvantageously provides additional support. This reference lacks sealing. Therefore, it is plausible that the ink will flow out of the cassette into the adjacent area of the wedge-shaped ink well. Also, a downwardly-directed handle attached to the back wall of the cassette of this reference makes the cassette difficult to handle, especially for wedge-shaped ink wells located below the operating plane.